<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<style>
    *{margin: 0;padding: 0}
    video{
        width: 100%;
        height: 240px;
    }
</style>
<body>
<video controls>
    <source src="https://www.runoob.com/try/demo_source/movie.mp4"  type="video/mp4">
</video>
</body>
</html>